Part 3, 1908] ROSACEAE 287 
10. Ivesia Muirii A. Gray, Proc. Am. Acad. 8: 627. 1873. 
Potentilla Muirti Greene, Pittonia 1: 106. 1887. 
Horkelia Muirii Rydb. Mem, Dep. Bot. Columbia Univ. 2: 148. 1898, 
Perennial, from a deep, rather thick root, crowned by an erect caudex 1-4 cm. high, 
which is covered with the remains of old leaves; stem 2-4 cm. high, scapose, few- 
flowered, filiform, silky-villous; basal leaves numerous, 2-3 cm. long, densely white- 
silky, terete and worm-like from the very numerous minute, densely imbricate leaflets ; 
cyme few-flowered, subcapitate ; hypanthium cupulate, 3 mm. in diameter, silky-villous; 
bractlets ovate, minute, less than one fourth as long as the ovate sepals; petals cuneate, 
shorter than the sepals ; stamens (5; filaments filiform. 
TYPE LOCALITY: Mount Hoffman, California. 
DISTRIBUTION : Known only from the type locality. 
ILLUSTRATION : Mem. Dep. Bot. Columbia Univ. 2: pl. 90. f. 6-10. 
11. Ivesia Chandleri Rydberg. 
Horkelia Chandleri Rydb. Bull. Torrey Club 28: 177. 1901. 
A low silky perennial, with very thick and woody root, and short cespitose caudex, with 
erect branches densely covered by the remains of old leaves; stems scapiform, slender, 
silky-villous, 7-16 cm. high; basal leaves numerous, 4-5 cm. long, densely silky, terete, 
worm-like from the numerous small crowded segments; flowers about 4 mm. in diameter, 
rather numerous, in subcapitate dense clusters; hypanthium cup-shaped, as well as the calyx 
densely villous; bractlets linear, about two-thirds as long as the triangular-ovate sepals, 
which are about 2 mm. long; petals yellow, linear, 1.5 mm. long, shorter than the sepals; 
stamens mostly 5; filaments subulate-filiform. 
TYPE LOCALITY: Mt. Goddard, California. 
DISTRIBUTION : Known only from the type locality. 
12. Ivesia Webberi A. Gray, Proc. Am. Acad. 10: 71. 1874. 
Potentilla Webberi Greene, Pittonia 1: 105. 1887. 
Horketia Webberi Rydb. Mem. Dep. Bot. Columbia Univ. 2: 149. 1898. 
Perennial, with a deep root, crowned with an erect, short, scaly caudex; stems several, 
slender, short, less than 1 dm. long, nearly scapose, more or less tinged with brown, glabrate; 
basal leaves 3-4 dm. long, many, pinnate, with 8-10 crowded pairs of leaflets, grayish-silky, 
but not densely so; leaflets about 1 cm. long, divided to the base into linear or lanceolate 
acute segments; petioles with long fine silky hairs; cyme subcapitate; hypanthium cupulate, 
tinged with brown, slightly silky, 4 mm. in diameter; bractlets linear or linear-lanceolate, 
shorter than the ovate or ovate-lanceolate sepals, which are about 4 mm. long; petals 
oblanceolate, yellow, scarcely equaling the sepals; stamens 5; filaments filiform. 
TYPE LOCALITY: Sierra Valley, California. . 
DisTRIBUTION: Northern Sierra Nevada of California and Nevada. 
ILLUSTRATION: Mem. Dep. Bot. Columbia Univ. 2: p/. 88, f. 5-9. 
13. Ivesia utahensis S. Wats. Proc. Am. Acad. 17: 371. 1882. 
Potentilla utahensis Greene, Pittonia 1: 162. 1888. , 
Horkelia utahensis Rydb. Mem. Dep. Bot. Columbia Univ. 2: 150. 1898. 
Perennial, with a woody but not very thick root, crowned by a cespitose caudex cov- 
ered with the remains of old leaves; stems several, about 1 dm. high, simple and few- 
leaved, glabrous below, glandular above; stipules broadly ovate, entire; basal leaves 
numerous, 5-8 cm. long, glabrous, pinnate, with 15-20 pairs of crowded leaflets, these 2-4 
mm. long, cleft to the base into 3-5, broadly oblong to spatulate, one-nerved segments ; 
stem-leaves few and very small; cyme rather dense and somewhat flat-topped ; hypanthium 
somewhat glandular-puberulent, cup-shaped, veiny, 3 mm. in diameter ; bractlets linear, a 
third shorter than the ovate or lanceolate-ovate sepals, which are 2-2.5 mm. long; petals 
yellowish, spatulate, scarcely exceeding the sepals ; stamens 5; filaments filiform. 
TyPE LOCALITY : Bald Mountain, Wahsatch Range, above Alta, Utah. 
DISTRIBUTION : Mountains of Utah. : . 
ILLUSTRATION: Mem. Dep. Bot. Columbia Univ. 2: p/. 91, f. 4. 
